1. Field of the Invention
The present invention relates to a solid-state image sensor and a method of manufacturing the same.
2. Description of the Related Art
Japanese Patent Laid-Open No. 2006-191081 discloses an image sensor formed by uniting a member constituting a light-receiving portion, and a member constituting a peripheral circuit which drives it to each other. The member constituting the light-receiving portion includes microlenses, color filters, photodiodes, transfer transistors, and metal lines. The member constituting the peripheral circuit includes metal lines to be connected to those of the light-receiving portion, a substrate on which a source/drain region is formed, an insulation film, a pad, and a connecting portion which extends through the insulation film and the substrate to connect the pad and the metal lines to each other.
In a configuration described in Japanese Patent Laid-Open No. 2006-191081, the connecting portion which extends through the substrate is in contact with the substrate, so a plurality of pads, if used, may be imperfectly insulated from each other. Although a method of forming a connecting portion after side faces defining through holes formed in the substrate are covered with an insulator is also available, an insulation film must be stably formed on the side faces defining deep through holes in this case.